/*  Copyright (C) 2014-2021 FastoGT. All right reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are
    met:

        * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
        * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the following disclaimer
    in the documentation and/or other materials provided with the
    distribution.
        * Neither the name of FastoGT. nor the names of its
    contributors may be used to endorse or promote products derived from
    this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <common/string_split.h>

#include <stddef.h>

#include <common/string_util.h>

namespace common {

namespace {

// Returns either the ASCII or UTF-16 whitespace.
template <typename Str>
BasicStringPiece<Str> WhitespaceForType();
#if defined(OS_WIN) && defined(BASE_STRING16_IS_STD_U16STRING)
template <>
WStringPiece WhitespaceForType<std::wstring>() {
  return kWhitespaceWide;
}
#endif

template <>
StringPiece16 WhitespaceForType<string16>() {
  return kWhitespaceUTF16;
}
template <>
StringPiece WhitespaceForType<std::string>() {
  return kWhitespaceASCII;
}

// General string splitter template. Can take 8- or 16-bit input, can produce
// the corresponding string or StringPiece output.
template <typename OutputStringType, typename Str>
static std::vector<OutputStringType> SplitStringT(BasicStringPiece<Str> str,
                                                  BasicStringPiece<Str> delimiter,
                                                  WhitespaceHandling whitespace,
                                                  SplitResult result_type) {
  std::vector<OutputStringType> result;
  if (str.empty())
    return result;

  size_t start = 0;
  while (start != Str::npos) {
    size_t end = str.find_first_of(delimiter, start);

    BasicStringPiece<Str> piece;
    if (end == Str::npos) {
      piece = str.substr(start);
      start = Str::npos;
    } else {
      piece = str.substr(start, end - start);
      start = end + 1;
    }

    if (whitespace == TRIM_WHITESPACE)
      piece = TrimString(piece, WhitespaceForType<Str>(), TRIM_ALL);

    if (result_type == SPLIT_WANT_ALL || !piece.empty())
      result.emplace_back(piece);
  }
  return result;
}

bool AppendStringKeyValue(StringPiece input, char delimiter, StringPairs* result) {
  // Always append a new item regardless of success (it might be empty). The
  // below code will copy the strings directly into the result pair.
  result->resize(result->size() + 1);
  auto& result_pair = result->back();

  // Find the delimiter.
  size_t end_key_pos = input.find_first_of(delimiter);
  if (end_key_pos == std::string::npos) {
    return false;  // No delimiter.
  }
  result_pair.first = std::string(input.substr(0, end_key_pos));

  // Find the value string.
  StringPiece remains = input.substr(end_key_pos, input.size() - end_key_pos);
  size_t begin_value_pos = remains.find_first_not_of(delimiter);
  if (begin_value_pos == StringPiece::npos) {
    return false;  // No value.
  }

  result_pair.second = std::string(remains.substr(begin_value_pos, remains.size() - begin_value_pos));

  return true;
}

template <typename OutputStringType, typename Str>
std::vector<OutputStringType> SplitStringUsingSubstrT(BasicStringPiece<Str> input,
                                                      BasicStringPiece<Str> delimiter,
                                                      WhitespaceHandling whitespace,
                                                      SplitResult result_type) {
  using Piece = BasicStringPiece<Str>;
  using size_type = typename Piece::size_type;

  std::vector<OutputStringType> result;
  if (delimiter.size() == 0) {
    result.emplace_back(input);
    return result;
  }

  for (size_type begin_index = 0, end_index = 0; end_index != Piece::npos; begin_index = end_index + delimiter.size()) {
    end_index = input.find(delimiter, begin_index);
    Piece term =
        end_index == Piece::npos ? input.substr(begin_index) : input.substr(begin_index, end_index - begin_index);

    if (whitespace == TRIM_WHITESPACE)
      term = TrimString(term, WhitespaceForType<Str>(), TRIM_ALL);

    if (result_type == SPLIT_WANT_ALL || !term.empty())
      result.emplace_back(term);
  }

  return result;
}

}  // namespace

std::vector<std::string> SplitString(StringPiece input,
                                     StringPiece separators,
                                     WhitespaceHandling whitespace,
                                     SplitResult result_type) {
  return SplitStringT<std::string>(input, separators, whitespace, result_type);
}

std::vector<string16> SplitString(StringPiece16 input,
                                  StringPiece16 separators,
                                  WhitespaceHandling whitespace,
                                  SplitResult result_type) {
  return SplitStringT<string16>(input, separators, whitespace, result_type);
}

std::vector<StringPiece> SplitStringPiece(StringPiece input,
                                          StringPiece separators,
                                          WhitespaceHandling whitespace,
                                          SplitResult result_type) {
  return SplitStringT<StringPiece>(input, separators, whitespace, result_type);
}

std::vector<StringPiece16> SplitStringPiece(StringPiece16 input,
                                            StringPiece16 separators,
                                            WhitespaceHandling whitespace,
                                            SplitResult result_type) {
  return SplitStringT<StringPiece16>(input, separators, whitespace, result_type);
}

bool SplitStringIntoKeyValuePairs(StringPiece input,
                                  char key_value_delimiter,
                                  char key_value_pair_delimiter,
                                  StringPairs* key_value_pairs) {
  return SplitStringIntoKeyValuePairsUsingSubstr(input, key_value_delimiter, StringPiece(&key_value_pair_delimiter, 1),
                                                 key_value_pairs);
}

bool SplitStringIntoKeyValuePairsUsingSubstr(StringPiece input,
                                             char key_value_delimiter,
                                             StringPiece key_value_pair_delimiter,
                                             StringPairs* key_value_pairs) {
  key_value_pairs->clear();

  std::vector<StringPiece> pairs =
      SplitStringPieceUsingSubstr(input, key_value_pair_delimiter, TRIM_WHITESPACE, SPLIT_WANT_NONEMPTY);
  key_value_pairs->reserve(pairs.size());

  bool success = true;
  for (const StringPiece& pair : pairs) {
    if (!AppendStringKeyValue(pair, key_value_delimiter, key_value_pairs)) {
      // Don't return here, to allow for pairs without associated
      // value or key; just record that the split failed.
      success = false;
    }
  }
  return success;
}

std::vector<string16> SplitStringUsingSubstr(StringPiece16 input,
                                             StringPiece16 delimiter,
                                             WhitespaceHandling whitespace,
                                             SplitResult result_type) {
  return SplitStringUsingSubstrT<string16>(input, delimiter, whitespace, result_type);
}

std::vector<std::string> SplitStringUsingSubstr(StringPiece input,
                                                StringPiece delimiter,
                                                WhitespaceHandling whitespace,
                                                SplitResult result_type) {
  return SplitStringUsingSubstrT<std::string>(input, delimiter, whitespace, result_type);
}

std::vector<StringPiece16> SplitStringPieceUsingSubstr(StringPiece16 input,
                                                       StringPiece16 delimiter,
                                                       WhitespaceHandling whitespace,
                                                       SplitResult result_type) {
  std::vector<StringPiece16> result;
  return SplitStringUsingSubstrT<StringPiece16>(input, delimiter, whitespace, result_type);
}

std::vector<StringPiece> SplitStringPieceUsingSubstr(StringPiece input,
                                                     StringPiece delimiter,
                                                     WhitespaceHandling whitespace,
                                                     SplitResult result_type) {
  return SplitStringUsingSubstrT<StringPiece>(input, delimiter, whitespace, result_type);
}

#if defined(OS_WIN) && defined(BASE_STRING16_IS_STD_U16STRING)
std::vector<std::wstring> SplitString(WStringPiece input,
                                      WStringPiece separators,
                                      WhitespaceHandling whitespace,
                                      SplitResult result_type) {
  return SplitStringT<std::wstring>(input, separators, whitespace, result_type);
}

std::vector<WStringPiece> SplitStringPiece(WStringPiece input,
                                           WStringPiece separators,
                                           WhitespaceHandling whitespace,
                                           SplitResult result_type) {
  return SplitStringT<WStringPiece>(input, separators, whitespace, result_type);
}

std::vector<std::wstring> SplitStringUsingSubstr(WStringPiece input,
                                                 WStringPiece delimiter,
                                                 WhitespaceHandling whitespace,
                                                 SplitResult result_type) {
  return SplitStringUsingSubstrT<std::wstring>(input, delimiter, whitespace, result_type);
}

std::vector<WStringPiece> SplitStringPieceUsingSubstr(WStringPiece input,
                                                      WStringPiece delimiter,
                                                      WhitespaceHandling whitespace,
                                                      SplitResult result_type) {
  return SplitStringUsingSubstrT<WStringPiece>(input, delimiter, whitespace, result_type);
}
#endif

}  // namespace common
